The major objective of this proposal is to delineate some of the fundamental mechanisms involved in the fibrotic process of chronic alcoholic liver disease. Major emphasis will be placed on various aspects of collagen metabolism and alterations which occur concurrently with the disease process. Tissue culture of human liver explants obtained by biopsy will be used to measure rate of collagen biosynthesis and the relative distribution of genetically distinct types of collagens produced during various stages of alcoholic hepatitis and cirrhosis. Subsequently, various agents, including collagen degradation peptides, lymphokines, cirrhotic liver extracts and BUDR will be added to culture media in an attempt to simulate the pathologic process in vivo. Fibroblasts and the injured parenchymal cells will be examined in culture to determine the rate of collagen synthesis and distribution of collagen types. Cellular alterations such as membrane phosphorylation and/or dephosphorylation, levels of cyclic AMP and specific cell-cell interactions will be monitored in terms of progressive liver fibrogenesis. Whenever possible, human tissue will be used as the primary source of hepatic tissue, but experimental rat liver cirrhosis with various dietary regimens such as CCl4 and alcohol feeding will be used. Complete characterization of basement membrane associated human liver collagen will also be attempted with special reference to the various stages of liver disease. These unique collagens will be isolated from limited pepsin digests of human liver after autopsy. Their amino acid composition, molecular weight, extent of glycosylation and content of specific CNBr-derived peptides will be determined. These studies are designed to identify molecular mechanisms of altered collagen metabolism which occur at the cellular level during the pathogenesis of alcoholic liver disease.